Furnace.



fue. 68mm.

Patented Dec. 3l, |9011.I

J. MCFARLANE E. D. STERNE.

FURNACE.

(In Model.)

(Application led Apr. 5, 1901.)

"U'NrTnn STATES 1 ATENT Trice.,

JOHN MCFARLANE AND EDVARD D. STERNE, OF VASIIINGTON, DISTRICT OFCOLUMBIA, ASSIGNORS OF ONE-HALF TO OBADIAII A. PURDEY, OF WASHINGTON,DISTRICT OF COLUMBIA.

FU RNACE.

SPECIFICATION forming part of Letters .Patent No. 689,901, datedDecember 31, 1901.

Application tiled April 5, 1901. Serial No. 54,497. (No model.)

T all whom, t may concern:

Beit known that we, JOHN MCFARLANE and EDWARD D. STERNE, citizens of theUnited States,lresiding at IV-ashington, in the District of Columbia,have invented new and useful Improvements in Furnaces, of which thefollowing is a specification.

Our invention relates to improvements in furnaces; and itconsists in thenovel feaio tures of construction hereinafter described, reference beinghad to the accompanying drawings, which illustrate one form in which wehave contemplated embodying our invention, and said invention is fullydisclosed in the following description and claims.

Referring to the drawings, Figure lis a vertical cross-section lookingfrom the front of the furnace. Fig. 2 is a vertical cross-sec tionlooking from the side of the furnace.

zo Fig. 3 is a plan view of the fire pot and grate,

and Fig. 4 is a detail view of the draft-closing plates with a portionof their operating mechanism.

The object of our invention is to provide z 5 an improved furnacewherein the draft which would ordinarily pass up through the fuel frombelow the grate is cut off and allowed to percolate through the fuelfrom all sides and a very small lportion permitted to pass up 3o underthe grate.

A further object is attained by our device. After the fire is startedand the coal-bed thoroughly heated the draft-closing plates are shut andthe draft passes through the open- 3 5 ings in the fire-pot and air isthoroughly mixed with the dames from the fuel, thereby making combustionmore complete and consuming any smoke which may rise from the fireitself or from fuel thrown on the same.

A represents the brickwork of a furnace. On this brickwork rests theboiler B. Below the boiler, inside the brickwork and secured to suitableangle-irons a, are the fire-pots C C. A space is left between the twofire-pots and also between each fire-pot and the adjacent Wall of thebrickwork. These spaces are closed at the top to prevent the escape ofair for a purpose hereinafter mentioned. The central space c is closedby the plate c', while the spaces c2 c3 are closed by the an gle-irons0;. 5o The baclgfront, and two sides of each of these tire-pots areperforated, as shown at a', for a purpose hereinafter described.Stationary grate-bars D are secured at the under edge of the fire-pots Cby suitable supports d d', mounted in the brickwork. In the frontandback of the furnace are plate-supports E E, in which are pivoted thedraft-closin g plates F F. (Shown in Fig. 4 of the drawings.) Thesedraft-closing plates are each swiveled to a short arm f, each of whichis in turn swiveled to a rod f2 in such a way that all of the plates Fare operated in unison thereby. The rod f2 extends across the front ofthe furnace under the grate and out through the brickwork through asuitable opening in the side thereof. A series of these draft-closingplates are arranged beneath each set of grate-bars, as is shown in Fig.l of the drawings. The space between the hre-pots is closed at thebottom by a set of secondary draft-plates G, similar to thedraft-closing plates. To the under side of these plates G are pivotedshort arms g, the lower ends of which are each pivoted to a rod e insuch a manner that the 75 plates G can be operated together to close thespace between the fire-pots. This rod g runs transverse of vthe furnacebeneath the grate and extends through and out beyond the brickwork for areason which will hereinafter appear.

The spaces at the sides of the lire-pots adjacent to side walls of thebrickwork are adapted to be closed at the bottom by means of the platesL, which have short arms 7c swiveled to the under side thereof. Theseshort arms are also pivoted to the rod gl and are adapted to be operatedtherewith.

The plates G are so arranged With respect to the plates L that both setsare adapted to be operated by one movement of the rod g.

A weighted lever f3, fulcrumed at f, is connected with the rod]C2 at f5and to the rod g' at f6. The weight X on the end of this lever f3 tendsto normally hold the draft-closing plates F in a closed position and theplates G and L in an open position, the object of which will hereinafterbe set forth.

The operation of the device is as follows: A fire is started on thegrate, with the draftclosing plates F open to allow the draft to pass upthrough the fire. When the bed of fuel becomes thoroughly heated, thesedraftclosing plates are closed and the secondary draft-closing plates Gand L simultaneously opened, thus forcingthe draft through the spacesbetween and around the fire-pots. The air then enters the perforationsin the said fire-pots and percolates through the fuel, thoroughly mixingair with the gas generated by lthe fuel, making combustion more completethereby and consuming any smoke which may rise from the re itself orfrom fresh fuel thrown on the same.

We have shown and described our invention as being applied to astationary boiler; but it may be arranged to operate in connection withmarine and locomotive boilers without departing from the spirit of ourinvention.

Having described our invention, whatwe claim, and desire to secure byLetters Patent,

`1. In a furnace, the combination with lthe combustion-chamber and thegrate, of a fire- 'draft through the grate, similarlymounted plates foropening the secondary draft and directing the same through saidperforations in said fire-pot, and means for operating both sets ofplates, substantially as described.

In testimony whereof We affix our signatures in presence of twoWitnesses.

JOHN MCFARLANE. EDWARD D. STERNE. Witnesses: ERNEST R. RUPPERT, GEORGEM. BOND.

